As a nickname, or as an insult. The sad truth is most people ACTUALLY think it's spelled that way.

Rouge is actually both a shade of red, and a type of makeup, however if you could magically alter it to rouge on the class names, many people wouldn't be able to tell the difference.

Wogue is a much funner nickname, however rouge is not only more well known, but most people don't even know it's just a nickname, or even misspelling. Rouge is possibly the most boring misspelling of classes in World of Warcrack, and why almost everybody misspells it's name so much escapes me.

"LF rouge to open a lockbox OMG PLZ PLZ PLZ OMG". <- The sad truth I see in trade every day.

"Ew gross so and so is wearing way too much rouge". <- The makeup.

"My favorite colors rouge whats yours?". <- The color

As a nickname: "Rouge sap X, watervendor sheep the moon thingy, loladin off tank if I die, durid keep us healed, and I the rawrrior shall tank".